Aldehyde condensation products of sulfonated aromatic compounds as cation exchange resins



Patented Apr. 27, 1948 ALDEHYDE CONDENSATION PBODUUI'S F SULFONATED AROMATIC COMPOUNDS AS CATION EXCHANGE RESINS I Jack T. Thurston, Riverside, Conm, assignmto American Cyanamid Company, New York, N. Y., a corporation oi Maine No Drawing. Application June 21, 1944, Serial No. 541,480

This invention relates to cation active materials, that is materials which exchange or extract by other means cations from fluidmedia.

An object of this'invention is to provide a substantially insoluble resin having a relatively high capacity for the absorption of cations.

This and other objects are attained by resinitying a mixture including a least one aldehyde selected from the group consisting of formaldehyde and furfural and a sulfonated compound having the cfollowing general formula:

in which R1 is a hydroxyaromatic radical of the benzene series, X is an activating group possessing a polar bond selected from the group consisting of CO-aliphatic, CO-aromatic,

-Co-aliphatic-aromatic, COOR, CN, and

NQ2, M is selected from the group consisting of metals, hydrogen and --H.NR2R3R4, and R, R2, Ra, and R4 are selected from the group consisting of hydrogen and organic radicals.

One method for preparing sulfonated compounds of the aforementioned type is by condensing a hydroxy benzaldehyde with a substance containing an active methyl group or an active methylene group and converting the resulting condensation product into a sulfonate by reaction with a bisulflte. The term sulfonate as used herein includes the hydrogen sulfonate. i. e., the sulfonic acid, as well as the metal, ammonia, and amine salts thereof. Y

The following examples are given by way of illustration and not in limitation. The proportions are in parts by weight and the Formaiin is an aqueous solution containing 37% formaldehyde.

EXAMPLE 1 Preparation of o-hydroxybenzalacetone 220 parts of ethanol are added to a mixture oi 244 parts (2.0 mols) of ,salicylaldehyde, 464 parts (8.0 mole) of acetone, and 600 parts of water at room temperature. A solution of 160 parts (4.0 mols) of sodium hydroxide in 400 parts of water are then added at such a rate that the.

7 Claims. (Cl. 260-49) ever. when about half of the alkali has been added. The solution becomes darker in color as the alkali is added until, when the addition is complete, it is a dark red. There is some precipitation of the sodium salt of the product. Stirring is continued for one hour and the reaction mixture then neutralized with 288 parts of glacial acetic acid. The product separates in the form of light yellow crystals which, after drying in a vacuum desiccator, melt at 128-132 C. and are obtained in a yield of 77% oi. the theoretical.

The above procedure is repeated except that the product is precipitated by passing carbon dioxide through the reaction mixture. The 2- hydroiwbenzalacetone so obtained in a yield of 54% melts at 135-138 0.

Upon recrystallization from benzene, pale yellow needles melting at 137-138 C. are obtained.

(EH-CHr-C-CH: SOaNa g H A mixture of 162 parts (1.0 mol) of 2'-hydroxybenzalacetone, 1M parts (1.0 mol) of sodium bisulfite, and 400 parts of water is placed in a vessel equipped with a stirrer and reflux condenser.

The mixture is heated to boiling and 47 parts of the monoethyi ether of ethylene glycol are added to cause complete solution. The solution is refiuxed for 3 hours and evaporated on a. steam bath under reduced pressure. The solution obtained, brown in color, is used without further purification in the preparation of resins.

The product may be obtained as a white crystalline solid by further evaporation and allowing the concentrated solution to stand for a Period or time.

Preparation of resin A solution 01' fiparts (0.06 mol) of concentrated hydrochloric acid in 48.6 parts (0.1 mol) of sodium l-(o-hydroxyphenyl)-3-ketobutane sulfonate is heated to C. at which temperature there is an evolution of sulfur dioxide. Heating is stopped and 16.2 parts (0.2 moi) of Formalin are added. The precipitate formed thickens to a thermoplastic material and later becomes hard. The mixture is heated for a total of a half hour at 75 C. The purple-black and brittle solid is removed from the liquid, broken up, and cured for 4 hours at 100 C.

Emma: 2

The above procedure of resin preparation is repeated except that the solution is cooled so that the temperature does not exceed 25 C. After the solution has stood for about 24 hours. a soft elastic cohesive violet-colored gel is formed which, at the end of about 96 hours, is firm and brittle. The gel is broken into small particles and cured for 4 hours at 50 C. and for 4 hours at 100 C. The resin has a capacity for the absorption or exchange of cations from aqueous media equivalentto about 5,600 grains of calcium carbonate per cubic foot of resin.

Exam 3 A resin is again prepared as in Example 1, this time using times the quantities of materials and maintaining the temperature at or below 15 C. during the preparation of the solution. The resulting resin has a capacity for absorbing or exchanging cations from an aqueous solution equivalent to about 8,700 grains of calcium carbonate per cubic foot of resin and a density of 26.6 pounds per cubic foot.

Exmmr 4 a formed. After 45 minutes, the solid material is removed from the solution broken up and cured for 4 hours at 100 C. The resulting cured product is purple-black and brittle.

EXAMPLE 5 Preparation of o-hydrozu-m-methoznbenzalacetonc CHI H A'mixture of 232 parts (4.0 mols) acetone and 1745 parts of 2.5% sodium hydroxide solution is added to 142 parts (1.0 mol) of 2-hydroxy-3- methoxybenzaldehyde and the light red colored solution stirred while 472 parts of sodium hydroxide solution are added over a period of one hour. After standing for about 72 hours the solutionis diluted with 4260 parts of water and acidified with 3454 parts of 5% hydrochloric acid. The yellow crystalline solid which separates is filtered oil, washed well with water and placed in a vacuum desiccator. The material melting at 65-70 C. is obtained in a yield of 69%.

Preparation of potassium I-(o-hudrozu-mmethowyphenyl) -3-lcetobutane salfonate A mixture 01.19 parts (0.1 mol) of o-hydroxym-methoxybenzalacetone. 11- parts (0.05 mol) of potassium metabisulflte (equivalent to 0.1 moi of from alcohol, it melts at 179 C.

This product may be resimfied in the same general manner as described in Examples 1-4.

EXAMPLE 6 Preparation of o-hydrozybenzalmethul ethyl ketone A solution of 258 parts (6.45 mols) of sodium hydroxide in 1000 parts of water is added to a mixture of 366 parts (3.0 mols) oi salicylaldehyde and 432 parts (6.0 mols) of methyl ethyl ketone v in 2000 parts of water and the solution is heated salt for the sodium salt.

for 3.5 hours at -85 C. The reaction mixture is diluted with water and neutralized with 5% hydrochloric acid while it is stirred and cooled with ice. The resulting precipitate which is partly gummy and partly crystalline is crystallized from benzene to give a product, melting at 108 C., in a yield of 41%.

Preparation of potassium 1-(o-h11drox1/phen1 D- 3-ketopentane sulfonate A mixture 01' 17.6 parts (0.1 mol) of o-hydroxybenzalmethyl ethyl ketone, 11.1 parts (0.05 mol) of potassium metabisulflte (equivalent to 0.1 mol of potassium bisulflte) and 65 parts of water is refluxed for 2 hours and evaporated to a small volume. The solid, which is formed on standing, is washed with alcohol, dried, and finally obtained in a yield of 61%. After two crystallizations from alcohol, the material melts at 134 C.

Preparation of sodium 1-(o-hndroxz pheng D-3- ketopentane salfonate The above procedure is repeated except that sodium bisulflte is used in place of the potassium metabisulflte, and larger quantities 0! all the reactants are used. The solution is evaporated to a small volume and the crystals obtained in a yield of 42% are washed with alcohol and dried.

Preparation of resin A solution of 124 parts (0.44 mol) of sodium l-(o-hydroxyphenyl) -3-ketopentane sulionate in parts of water is prepared and cooled to 10 C. and 26 parts (0.27 mol) of concentrated hydrochloric acid which has been cooled to 10 C. are added. 71 parts (0.88 mol) of Formalin which has been cooled to 1 are added. The solution is then removed from the ice bath and allowed to stand. The firm gel which forms after one day is broken into small particles and cured for 4 hours at 50 C. and for 16 hours at 100 C. The product has a capacity for absorbing cations from solution equivalent to about 3,300 grains 0! calcium carbonate per cubic foot of resin and a density of 14.3 pounds per cubic foot.

A similar product may be prepared-by substituting an equivalent proportion of the potassium Preparation of o-hydroaybenzalmethyl isobuiyl ketone A solution of 86 parts (2.15 mols) of sodium hydroxide in 1000 parts of water is added to 122 parts (1.0 mols) of saiicylaldehyde dissolved in 200 parts of (2.0 mois) of methyl isobutyl ketone, and the mixture is heated for 2 hours at 85-90 C. The reaction mixture is diluted and acidified with 5% hydrochloric acid. The product, which is filtered, washed with water, and dried in a vacuum desiccator, has a melting point of 101 C. and is obtained in a 51% yield.

Preparation of potassium l-(o-hydrozyphenub- 3-keto-5-methvlhexane sullonate A mixture of 20.4 parts (0.1 mol) of o-hydroxybenzalmethyl isobutyl ketone, 11.1 parts (0.05 mol) of potassium metabisuifite and parts of water isrefluxed for 2 hours. The solution is cooled and on standing 9. solid obtained in a yield of 56% is separated, washed with acetone and then dried.

Preparation of resin A solution of 146 parts (0.45 mol) of potassium-l-(o hydroxyphenyl) -3-keto 5 methylhexane sulionate in 150 parts 01 water is prepared by heating the mixture on a steam bath. Upon cooling to 15 C., a partial precipitation occurs. 26 parts (0.27 mol) of concentrated hydrochloric acid which has been cooled to 15 C. are then added, followed by '73 parts (0.9 mol) of Formaiin which'has also been cooled to 15 0. Only a part of the solid material is dissolved and stirring is continued for 6 hours at the end of which time a small amount of solidis still,pres-' .ent as a fine suspension. After about 24 hours a wherein R1 is a hydroxy substituted aromatic radical of the benzene series, X is an activating group possessing a polar bond such as, for example, CO-aiiphatic, CO-aromatlc, CO- -aliphatic-aromatic, -COOR, -CONRR, CN, and -NO2, M is a hydrogen, a metal or iurcus acid. On the other hand, ketones or other substances having two active groupeither methyl or methylene, may be combined with 2 mols of hydroxy aromatic aldehyde and the resuiting compound in turn treated with one or two male of a bisulilte or sulfurous acid. In these latter cases. the sulfonates would be represented by the following general formulae, respectively:

R. o n m-on-dn-iL-dn-cm-n solM sour and mixtures of the sulfonic acidmay be used in the condensation product to produce a correhaving an active methyl group or an active methgen or organic radicals. The R and X groups may include additional hydroxy-substituted aromatic radicals of the benzene series and/or additional sulfonate groups. Any of the Rs in the above formula or in the succeeding formulae may be any desired organic radical since they donot form the essential characteristics of my compositions.

It is apparent that one mol of a hydroxy benzaldehyde may be reacted with one mol of a ketone or other active compound and the resulting compound reacted with one mol of a bisulflte or sulplace of the individualcompounds if desirable.

One large group of sulfonic acids which may be employed are those formed by condensing a hydroxy aromatic aldehydewith a ketone and subsequently adding a bisuifite or sulfurous acid to spending sulfonate or sulfonic acid. Ketones yiene group other than those employed in the previous examples may be used, e. g., methylhexyl ketone, di-n-butyl ketone, acetophenone, methyl benzyi ketone, etc. Furthermore, mixture of the various ketones maybe employed.

The ketones are merely illustrative of a large number of substances containing an active methyl or an active methylene group which may be condensed with a hydroxy aromatic aldehyde to yield an unsaturated compound to which a bisuiilte or sulfurous acid may be added. Broadly speaking the substances which may be reacted with a hydroxy aromaticaldehyde have the (ollowing general formula:

Bic-R where R is hydrogen or anorganlc radical, and X is an activating group possessing a polar bond. The condensation of a hydroxy aromatic aldehyde with a compound of this type resultsin a substance of the following general formula::

Rr-CHgR-X where R1 represents a hydroxy substituted aromatic radical of the benzene series and R and X i acid, pyruvic acid, phenylacetic acid, oxaiacetic acid, 3,5-dinotro-o-toiuic acid, the esters of these acids (such as the methyl, ethyl, .benzyl and phenyl esters) and their amides; crotonaldehyde, sorbic aldehyde, proplonaldehyde, ,heptaldehyde, succinic aldehyde, phenylacetaidehyde; acetonitrile, propionitrile, crotonic nltrile, su-

recited in the examples are merely illustrative of s a large number of hydroxyaromatic aldehydes of the benzene series which may be condensed with compounds containing an active methyl or methylene group or groups.' Hydroxyaromatic aldehydes of the benzene series containing additional substituent such as, for example. hydroxyl, sulfoxy, halogen, alkyl, aryl, alkaryl, aralkyl, and the like are equally suitable.

A compound of the foreging type may be conment with sulfur dioxide in a solvent medium including water or by treatment with a bisulflte. Suitable bisulfltes include: sodium bisulflte, potassium bisulflte, ammonium bisulflte or any other desirable metal bisulflte such as calcium bisulflte. In general, the alkali metal bisulfltes are preferred. The hydrogen sulfonates may beconverted to the corresponding metal, ammonium or amine salts if desired.' Examples of amines useful in the formation'of such salts are: methyl :5

amine, dimethyl amine, pyridine. triethyl amine,

the mono-, di-, and tri-ethanolamines. etc.

Another method of producing the sulfonic acids or sulfonates is by treatment of the benzyl' idene compounds with a hydrohali'cle followed by so treatment with sodium sulfite or other metal sulfites. Thus, for example, hydrogen chloride may be added to benzylidene acetone and the re sulting material treated with sodium suliite.

Still another type of sulfonate may be pre- 85 pared by the condensation of a hydroxyben'zalde 'hyde with aeetonesulfonic acid followed by re action with a bisulflte. The sulfonates may be prepared from the benzylidene compounds by reaction with bisulflte 40 or sulfurous acid at temperatures ranging upwards from room temperature. In most in stances, the reaction is advantageously carried out at a temperature between about 70 C. and

about 130 0. although temperatures as. low as room temperature may be employed. If sulfur dioxide be used the reaction is preferably carried out under pressure, e. g., 25-l00#/sq. in. and/or at relatively low temperature such as about 20 C. The time of reaction varies some- 59 what according to the compatibility of the reactants. Thus. if a homogeneous solution of the reactants be employed, the reaction will usually be completed in from about one-half hour to about 2 hours. On the other hand, if

the solution of the reactants is not homogeneous. 6-8 hours or even more may be required. Gen- Y eraily, water is employed as the solvent medium for the bisulflte or sulfurous acid and the benzylidene compound, but if they are not sufllciently soluble therein other solvents may be used. Mixtures of water and water-miscible organic solvents are especially suitable since the water is a good solvent for the bisulflte or sulfurous acid,

while the organic solvent is a good solventfor as the benzylidenecompoundplixamples of suitable solvents ,are methanol, ethanol, propanol, isopropanol, tertiary butanol, dioxane, the lower albl mono-ethers of ethylene glycol and diethylene glycol, such as monoethyl ether of 'ethyl- 7 ene glycol, the mono-butyl ether of diethylene glycol, etc. Furthermore, inert ketones may be employed as solvents for the reactants in the production of the sulfonates.

In some instances it may be desirable emto be used as a cation exchanger where, for example, alkaline earth metals are exchanged'for sodium. However, my invention is not limited to verted to the corresponding sulfonate by treat- 15 may .be present.

'I'he sulfonates described above are preferably resinfled with formaldehyde or furfural or a mixture of the two. Obviously, the formaldehyde may be replaced by a polymer of formaldehyde or a substance yielding formaldehyde. Moreover, a portion of the formaldehyde .or furfural may be replaced by other aldehydes including acetaldehyde, butyraldehyde, heptaldehyde, crotonaldehyde, acrolein, benzaldehyde, etc. If a mixture of aldehydes is used, I prefer that it comprise a major portion of furfural and/or formaldehyde.

"I'he'molal ratio of aldehyde to sulfonate may be varied depending on the desired properties. Usually, molal ratios of aldehyde to sulfonate between about 1:1 and 3:1 are preferred. The

molal ratio is adjusted within the aforementioned range taking into consideration the facts that swelling and solubility increase toward the: low end of the range, while activity decreases toward the high end of the range.

The sulfonates may be condensed with furfural, Formalin or other aldehyde under acid, neutral or alkaline conditions, followed by gelation as illustrated in the foregoing examples. The gelation maybe effected in an acid or alkaline me- 'dium; however, from a practical point ofview either an acid or an acid salt is often used to induce gelation. For this purpose, strong mineral acids such as sulfuric acid, hydrochloric acid or ratios of acid to sulfonate greater than 1:1 be

employed some activity may be lost because of the fact that some sulfur dioxide may split out, especially if the temperature be high.

After gelation of the sulfonate-aldehyde condensation product, the gels are preferably aged at room temperature until sufliciently hard to be ground into small particles. The gel is ground to any desired size, e. g., to pass through an 8-12 mesh screen. The ground gel isdried and cured by heating in any suitable manner. The drying and curing process may be carried out at temperatures between about 15 C. andabout 200 C. The time required will, of course, vary somewhat with temperature. Generally, from about a half hour to about twenty-four'hours is sufllcient. I

At least part of the drying and curing operation is preferably carried out at a temperature of at least C.

I: desired. other materials which contribute gelation to a suitable carrier such as diatomaceous earth, clays, charcoal, etc. I active resin is spread on'the surface of a rela'-- tively inert material and this enables one to employ a smaller quality of resin than otherwise to obtain the same active area. 1 The granular resinous materials prepared according to my invention, and particularly those having a particle size less than 8 mesh, are useful in the removal of cations from fluid media, especially aqueous solutions. The resins may be used in the hydrogen-activated form to remove cations from solutions of bases. My resinous cation-active materials may also be employed as exchange materials in accordance with the principles applied to the use 01 the natural and synthetic zeolites. Thus, the resin may be activated with a sodium salt such as sodium chloride and upon contact with a solution containing calcium, magnesium or other cations, an exchange of the latter ions for the sodium ions takes place.

The activating solutions or regenerating solutions are dilute acid solutions or dilute salt so1utions, e. g., about 0.2%--10%v of sulfuric acid.

. hydrochloric acid, sodium chloride, potassium chloride, etc.

To be sufiiciently insoluble for practical use in the art of water purification, a resin should have a sufllciently low solubility that it will not be dissolved away rapidlyby the solution to be treated.

Thus, water should not dissolve more than about 1 part of resin in 1,000 parts of water when passed through a bed of resin (after the first cycle comprising an activation, exhaustion and reactivation of the'resin) My resinous materials are useful for a wide variety of purposes. Some of the uses which may be mentioned by way of example are: water purlfication; purification of sugar juices; purification of water from lead pipes; removal of heavy metal ions from food, beverages and pharmaceutical products; decolorization of solutions containing coloring matters, etc. My condensation products may also be employed to recover valuable metal cations from dilute solutions. e. g., gold from sea water, chromium from chrome tanning liquors,silver from photographic baths, etc. Another important application of my materials is in the absorption or adsorption of gases such as ammonia, the amines, e. g., triethyl-amine, methyl amine, etc... from fluid media either dissolved in a liquid, or from vapors.

.My resinified sulfonic acids may be used in re-- duction processes such as in reducing ferric ions to ferrous ions, in reducing manganese ions to a lower degree of oxidation, and. in reducing other cations to the metallic state. as well as for many other reduction purposes.

Obviously, many variations in the processes and compositions described above may be made without departing from the spirit and scope of the invention as defined inthe appended claims. For instance, it will be apparent that in Examples 6i and 7, the initial condensation may occur on In thisway, the

either .of the active methyl or methylene groups of the ketone and the product obtained in Example 6 for instance might just as well be represented by the formula: A

A mixture of compounds of both isomeric :tormulae may also be obtained. For simplification only one isomeric form of the compounds has been set out but it is to be understood that the composition inay have either of the isomeric forms or it may be a mixture containing both isomeric forms.

I claim:

1. A granular water-insoluble composition of matter comprising the granulated gelled and water-insolubilized products of reaction of a mixture including formaldehyde and sodium 1-(0- hydroxyphenyl) -3-ketobutane sulfonate having the formula on-cm-o-oni OiNa in a molar ratio of from 1:1 to 3:1.

2. A granular water-insoluble composition of matter comprising the granulated gelled and water insolubilized products of reaction of a mixture including formaldehyde and sodium l-(o.

hydroxyphenyl) -3,-ketopentane sulfonate having, in one of its isomeric forms, the formula,

in a molar ratio of from 1:1 to 3:1.

3. A granular water-insoluble composition of matter comprising the granulated gelled and CHCHg-C-CH:CH(CH:)2

03K on in a molar ratio of from 1:1 to 3:1.

4. A granular water-insoluble composition of matter suitable for the removal of cations from liquid media and comprising the granulated gelled and water-insolubilized products of reaction of a mixture including formaldehyde and a member of the group consisting of sulfonated compounds having the following general formula 1 Rn-(fH-CHt-O-alkyl soar where R1 is an aromatic radical of the benzene series nuclear substituted with a hydroxyl group, and their alkali and alkaline earth metal salts. their ammonium salts, and their organic amine salts, the molar ratio of aldehyde to sulfonated compound being from 1:1 to 3:1.

5. A process of preparing a granular water-insoluble composition of matter suitablefor the removal oi cations from liquid media which comprises reacting formaldehyde with a member ofthe group consisting of sulfonated compoun having the following general formula where R1 is an aromatic radical of the benzene series nuclear substituted with a hydroxyl group, and their alkali and alkaline earth metal salts. their ammonium salts, and their organic amine salts in a molar ratio of from 1:1 to 3: 1, aldehyde to sulfonated compound, gelling the resulting condensation product, heating the gel thus obtained until it is insoluble in water, and granulating the product.

6. A granular water-insoluble composition of matter suitable for the removal of cations from liquid media and comprising the granulated gelled and water-insolubllized products of reaction of a mixture including at least one aldehyde selected from the group consisting of furfural and formaldehyde and a member of the group consisting ,of sulfonated compounds having the following general formula in which R1 is an aromatic radical of the benzene series nuclear substituted with a hydroxyl group and their alkali and alkaline earth metal salts. their ammonium salts, and their organic amine salts, the molar ratio of aldehyde to sulfonated compound being from 1:1 to 3:1.

7. A process of preparing a granular water- 12 insoluble composition of matter suitable for the removal of cations from liquid media which comprises reacting at least one aldehyde selected from the group consisting of furfural and formaldehyde with a member of the group consisting of sulfonated compounds having the following general formula m-cn-cnr-o-slx i 0.1; i) in which R1 is an aromatic radical of the benzene series nuclear substituted with a hydroxyl group and their alkali and alkaline earth metal saltl. their ammonium salts. and their organic amine salts, the molar ratio of aldehyde to sulfonaiml compound being from 1:1 to 3:1, gelling the resulting condensation product, heating the gel thus obtained until it is insoluble in water, and granulating the product.

JACK T. 'I'HURSTON.

REFERENCES CITED The following references are ofrecord in the flle of this patent:

UNITED STATES PATENTS Name T 

